Air-pressure gauge



July 20, 1926.

L'. A. HALLSTEAD AIR PREssURE GAUGE Filed May 27, 1925 1 and provided in the passage 27 to act as a stop tor the plunger therein, and 33 are a pair of libre or rubber washers of the same diameter as the passage 27 and inserted thereinto one on either side of the flange 32. 34 is a plug which is inserted into the lower end'of the passage 27, and 35 is a spiral spring interposed between such plug and the lower face of the cone shaped member 29, such spring being adapted to restore the plunger to its uppermost or closed valve position when the button132 is released as is shown in Figure 3. 'y

The inner end of casing 1 is formed to provide an air inlet valve chamber 36, the outer end of which is internally threaded and receives the threaded bushing 37 upon which the end of the air line hose is secured. 38 is a circular passage extending from the inner end of the inlet valve cham ber 36 to the vertical passage 27, such oriice being opposite the stem when the plunger is in the uppermost or inoperative position. 39 is a circular valve having its inner lace recessed to receive the rubber washer 40 which engages a circular lip 41 upon the inner end ot the chamber 36, and 42 is a valve stem which is centrally secured to the valve 39 and slidable in the passageway when the valve is opened. 43 is a spiral spring interposed between the outer face oi the valve 39 and the bushing 37, such spring being provided to keep the lac-e oiI the rubber washer 40 in close contact with the lip 41 when the valve is closed.

For preventing the air entering the air pressure gauge whilst the tire is being inilated, l incorporate the following described device in my nozzle. ln the passageway 15,

a rod 44 is provided, one end of such rod being designed to project from the passage l5 into the transverse bore 27 and be in Contact with the lower cone shaped member 29 of the plunger, the other end of the rod being designed to project into the nozzle chamber 2 being turned upwardly and carrying a circular plunger 45 upon its upper end. 46 is a reduced portion preferably constructed of rubber or like material, and centrally disposed upon the inner lace oil the plunger 45, and 47 is a spiral spring interposed between the outer tace oit the plunger 45 and the inner iace of the lock nut 11. 48 is a circular recess centrally positioned in the outer lace of the bushing 16, being of the same diameter and adapted to receive the portion 46 when the plunger 45 moves inwardly to close the end or the orice 18 and prevent air entering the air pressure gauge.

rlhe operation ol my device is as Jlollows:

When the nozzle is applied to the automobile tire valve in the usual manner, the manually actuated plunger is in the posi:` tion illustrated in Figure 3, the valve 39 being closed and the plunger 45 being re- .;v nasales moved from the bushing 16 as the rod 44 is pushed outwardly by the cone shaped member 29 which is in its uppermost position. As the tire valve is opened by means of the plunger 6, the air from the tire enters the nozzle passing inwardly through the passage 13 into the nozzle chamber 2 and from thence through the passage 18 into the rubber sleeve 22 expanding such sleeve longitudinally and moving the sleeve 19 along the cylindrical chamber 14 and as the exterior or' the slot 25 is suitably graduated the air pressure of the tire will be shown.

lf it is seen that the tire requires further inlating the button 132 is depressed` its movement causing the conical portions 28 and 29 to move downwardly into the position shown in Figure 2. lt will be seen that as the conical portion 28 moves downwardly, the valve stem 42 will be pushed outwardly into the direction of the orifice 40 andthe valve opened which will permit the air pressure from the air line to pass around the valve and valve stem through the passageways 38, 27, and 15, and trom thence through the passage 13 into the tire valve in the usual manner. While the valve 39 is being opened, the plunger 45 will close the orilice 18 in the bushing 16 as the rod 15 will be permitted to move inwardl under the influence of the spiral spring 4 as the conical member 29 moves downwardly. lt will thus be seen that while the tire is being inflated, no air is permitted to enter the air pressure gauge. o i

en 1t is considered that the tire is sulliciently initiated and the air pressure in the tire required to be taken. the button 132 is released and the cone shaped members 28 and 29 will move upwardly under the induence or the spiral spring 35. As they malre this movement, the valve 39 will close, thus cutting ott' the passage ol air from the air line and the rod 44 and the plunger 45 will move outwardly through the upward movement of the cone shaped member 29, thus the air from the tire will be again admitted to the valve as before described and the air pressure otn the tire recorded.

Since the introduction el balloon tires it has been found dillicult to insure that one gauge will accurately show both low and high pressures, so to overcome this dilhculty we have inserted the iral spring 24 between the sleeve 19 and the bushing 16 as bei-'ore described. When the gauge is in the inoperative position, this spring is under compression, and when air is admitted under low ressure to the gauge, it assists 'pushingl t ie sleeve 19 along the' passageway 14. en a redetermined sufficiently high pressure has een reached, the sleeve 19 to which the end of the spring 24 is attached will travel to a point where the other end of the spring will not be in contact with the lll@ lll

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mennen bushing lo as illustrated in Figure 3 and therefor vvill not further assist the gauge movement.

From the foregoing description, it "will be seen that l have 'devised a very simply constructed air line nozzle and tire pressure gauge which will be of great value to motorists in the saving of both time and trouble. Furthermore, I have devised means for preventing the entry of air to the pressure gauge during the process ol iniating the tire and have thus eliminated a continual lstrain on the gauge.

My device also insures that the motorist records the correct air pressure in his tire, and not the air pressure in the air line., which is very often the case where no means is provided lor cutting olf the air line pressure from the air pressure gauge, during the recess ot imdation.

ll hat l claim for my invention is l. A combined air line nozzle and pressure gauge comprising a substantially tubular casing presentin an inlet valve chamber at one end, a nozze chamber at the opposite end, a longitudinal cylindrical chamber closed at its inner end and opening at its outer end into the nozzle chamber, an air assage paralleling the cylindrical chamcr and connecting the nozzle chamber `with the air inlet chamber., a valve coni trollingcommunication between the air inlet chamber and the air passage, a sliding gauge operable in the cylindrical chamber in response to air pressure in the nozzle chamber, a manually controlled valve operating in the nozzle chamber and controlling; communication thereof with the aforesaid cylindrical chamber and a nozzle secured in and closing the nozzle chamber but removable therefrom to ve accese to both the gauge and the valve operating in the nozzle chamber.

2. A combined air line nozzle and pres'- sure gauge comprising a substantially tubular casing present-ing an inlet valve chamber at one end, a nozzle chamber at the opposite end, a longitudinal cylindrical chamber closed at its inner end and communicating at its outer end with the nozzle cha-mber, a transverse bore formed in the casing between the closed end ol the cylinder and the inlet valve chamber, an air passage par alleling the cylindrical chamber and connecting the nozzle chamber with the transverse bore., a normally closed valve located in the inlet chamber and controlling communication thereof with the transverse bore, a stem carried by the valve and protruding into said bore, a sliding gauge operable in the cylindrical chamber in response to air pressure in the nozzle chamber, a normally closed valve controlling7 communication between the nozzle chamber and the open end ol the cylindrical chamber, a stem carried by the last named valve and ending through the air passage into said transverse bore, a manually operable plunger recipro'r cal in said bore and formed with spaced conical portions adapted for sliding engagement with said valve stems to move the valves to o en position, the arrangement of said conica portions vvith reference to the valve stems being such that when one valve is open the other valve is closed whereby either the air passage or the gauge may be placed in communication wit of a tire, anda nozzle secured in the nozzle chamber and removable therelrom to give access to the gauge and to the valve operan ing in said nozzle chamber.

LEON A HALLSTEAD.

the interior dll lill 

